Natural increase. Put simply, natural increase is the difference between the numbers of births and deaths in a population; the rate of natural increase is the difference between the birthrate and the death rate. Given the fertility and mortality characteristics of the human species (excluding incidents of catastrophic mortality), the range of possible rates of natural increase is rather narrow.
For a nation, it has rarely exceeded 4 percent per year; the highest known rate for a national population—arising from the conjunction of a very high birthrate and a quite low death rate—is that experienced in Kenya during the 1980s, in which the natural increase of the population approximated 4.1 percent per annum. Rates of natural increase in other developing countries generally are lower; these countries averaged about 2.5 percent per annum during the same period. Meanwhile the rates of
natural increase in industrialized countries are very low: the highest is approximately 1 percent, most are in the neighbourhood of several tenths of 1 percent, and some are slightly negative (that is, their populations are slowly decreasing). The rate of population growth is the rate of natural increase
combined with the effects of migration. Thus a high rate of natural increase can be offset by a large net out-migration, and a low rate of natural increase can be countered by a high level of net in-migration. Generally speaking, however, these migration effects on population growth rates are far smaller
than the effects of changes in fertility and mortality. An important and often misunderstood characteristic of human populations is the tendency of a highly fertile population that has been increasing rapidly in size to continue to do so for decades after the onset of even a substantial decline in
fertility. This results from the youthful age structure of such a population, as discussed below. These populations contain large numbers of children who have still to grow into adulthood and the years of reproduction. Thus even a dramatic decline in fertility, which affects only the numbers at age zero, cannot prevent the continuing growth of the number of adults of childbearing age for at least two or three decades. Eventually, of course, as these
large groups pass through the childbearing years to middle and older age, the smaller numbers of children resulting from the fertility decline lead to a moderation in the rate of population growth. But the delays are lengthy, allowing very substantial additional population growth after fertility has declined. This phenomenon gives rise to the term population momentum, which is of great significance to developing countries with rapid population growth and limited natural resources. The nature of
population growth means that the metaphor of a “population bomb” used by some lay analysts of population trends in the 1960s was really quite inaccurate. Bombs explode with tremendous force, but such force is rapidly spent. A more appropriate metaphor for rapid population growth is that of a glacier, since a
glacier moves at a slow pace but with enormous effects wherever it goes and with a long-term momentum that is unstoppable. The most important characteristics of a population—in addition to its size and the rate at which it is expanding or
contracting—are the ways in which its members are distributed according to age, sex, ethnic or racial category, and residential status (urban or rural).  The natural increase in population, from the CIA World Factbook, 2017.
In Demography, the rate of natural increase (RNI), also known as natural population change, is defined as the birth rate minus the death rate of a particular population, over a particular time period.[1] It is typically expressed either as a number per 1,000 individuals in the population[2] or as a percentage.[3] RNI can be either positive or negative. It contrasts to total population change by ignoring net migration. This RNI gives demographers an insight into how a region's population is evolving, and these analyses can inform government attempts to shape RNI. Examples[edit]Suppose a population of 5,000 individuals experiences 1,150 live births and 900 deaths over the course of one year. To show the RNI over that year as a percentage, the equation would be (1,150 – 900) ÷ 5,000 = 0.05 = +5% To show the RNI as a number per 1,000 individuals in the population, the equation would be (1,150 – 900) ÷ (5,000/1,000) = 250 ÷ 5 = +50 It can also be shown as natural births per 1,000 minus deaths per 1,000 (1,150 ÷ 5) – (900 ÷ 5) = 230 – 180 = +50 To convert the RNI per 1,000 population to a percentage, divide it by 1,000. The equation would be +50 ÷ 1,000 = 0.05 = +5% Uses[edit]The rate of natural increase gives demographers an idea of how a region's population is shifting over time. RNI excludes in-migration and out-migration, giving an indication of population growth based only on births and deaths. Comparing natural population change with total population change shows which is dominate for a particular region. Looking at this difference across regions reveals those that are changing mainly due to births exceeding deaths and those changing mainly due to migration. The map shows just such an analysis for the US.[1] Most Influential Component of Change for US Counties That Gained Population Between 2014 and 2015 The trend of RNI over time can indicate what stage of the Demographic Transition Model (DTM) a region or country is in. National efforts to affect RNI[edit]Government attempts to shape the RNI of a region or country are common around the world.[4] Policies can either encourage or discourage an increase in birth rates. For example, during the COVID-19 crisis Singapore offered families a “pandemic baby bonus” to encourage a higher birth rate, therefore increasing RNI.[5] The US has considered similar policies.[6] Another example was China's one-child policy, intended to decrease birth rates, therefore decreasing the RNI.[7] A country with a good infrastructure to support families, women's health, and maternal/child health would likely have lower death rates from infant or maternal mortality, which would increase RNI. See also[edit]
References[edit]
What statement best describes regional variations in health care throughout the world?What statement best describes regional variations in health-care throughout the world? Government expenditures on health care are highest in countries with high GDPs.
In which stage of the demographic transition are the highest natural increase rates found?Chapter 2. Which would be a likely result of an increase in a country's physiological density?We know that the higher the physiological density is, the more pressure people put on the land to produce enough food to survive. It also suggests that the available agricultural land is being used by more people, and it may reach its output limit sooner than a country that has a lower physiological density.
Which of the following statements is true about the total fertility of a society?Which of the following is a true statement about the total fertility of a society? The total fertility of a society decreases as the society progresses throughout the demographic transition.
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Which of the following statements about regional variations in the natural increase rate is true?
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